This investigation concerns the measurement of binocular visual capabilities in normal and Siamese cats. We are investigating the behavioral, electrophysiological, and clinical implications of binocular vision in these organisms. Our studies include the behavioral testing of capabilities, such as acuity and stereopsis, the measurement of response properties of single neurons in the visual cortex and the measurement of interocular alignment exhibited by these two organisms. Utilization of this multilevel strategy will provide us with information concerning the etiology of strabismus, implications of albinism, and the neurophysiological consequences of these visual anomalies. This data will hopefully suggest new modes of remediation for binocular visual anomalies in humans.